GM ECM TBI Questions with more information

[Joe Boucher]

If I understand what you did, you pulled a 2.8 TBI engine out from under
the TBI system and slipped a 4.3 in it's place.  As long as the throttle
body and the injectors are sized correctly, it should at least start.

Let's get real basic.  Did you check all of the ecm fuses?  I remember
one for the ECM and one for the injectors.  Could you have crossed a
wire and blown a fuse?

If the engine check light doesn't blink, then either the ecm isn't being
powered or it's dead.  The ecm grounds the light, in other words the
circuit path is battery, light, ecm controlled grounding switch.  To
check the light you must ground the circuit not provide power to it.  (I
tried to power the circuit.  Been there, done that.)

Joe Boucher
'70 RS/SS Camaro  '81 TBI Suburban